The invention is directed to infrared systems. Infrared detectors as used in current infrared systems, such as FLIRS, are presented with two types of radiation: (1) radiation of interest and (2) background noise. In general, a cold shield is a blocker which blocks background radiation to allow the infrared detector being shielded a better background for detecting radiation of interest. The effectiveness of a cold shield is dependent upon its geometry and position with respect to the detectors.
The prior art for controlling reflection and diffraction in the plane of infrared detectors involves tilting the detector array and dark mirror coating the area around the detectors. This area is not flat so the dark mirror coating (hereinafter called "DMC") performance is not repeatable nor reliable. The prism of the invention is a novel approach to the control of reflection and diffraction because it tilts the surface of the detector array optically. DMCs are applied to the prism surfaces which are flat and smooth. This provides optimum performance of the DMCs. DMCs on the prism can be configured to hide the metal contacts of the detector array and provide increased detectivity (hereinafter called "D*") by cold shielding the detectors between elements.